Whining noise from Dash AC Fan

[Ronvp]

I am new to this forum and just (December 2013) got my 2013 Discovery 40X. Bought it used with 6500 miles on it.

I have now taken it on 2 small (about 600 mile) trips and noticed that when I run the dash AC, it all works great, but I hear a whining noise every time the fan or compressor kicks in. It sounds like noise you here from a hydraulic pump.. It comes from the compressor area. When inside the cab, you can barely hear it, but outside it is very audible.

Does anybody know if you are suppose to here such a load noise when the fain/compressor runs?

Appreciate the help..

Ron

[bruceisla]

Originally Posted by Ronvp

I am new to this forum and just (December 2013) got my 2013 Discovery 40X. Bought it used with 6500 miles on it.

I have now taken it on 2 small (about 600 mile) trips and noticed that when I run the dash AC, it all works great, but I hear a whining noise every time the fan or compressor kicks in. It sounds like noise you here from a hydraulic pump.. It comes from the compressor area. When inside the cab, you can barely hear it, but outside it is very audible.

Does anybody know if you are suppose to here such a load noise when the fain/compressor runs?

Appreciate the help..

Ron

I think you'll need to define the area of the sound ...I am assuming you are diesel ... normally, the compressor is in the rear (on engine), the dash fan is under passenger dashboard, the vacuum pump is somewhere on the firewall (usually over generator), and the condenser fan is usually lower on chassis (roughly in area of passenger seat underneath). All of these make noise and the locations of components are variable. You can try running the dash defroster without A/C and see what happens. The defroster will utilize the dash fan and vacuum pump.

[al2ride]

If you hear it when the AC is off then it's usually a bad idler pulley or clutch bearings in your compressor. If it happens when you turn it on (clutch on compressor engaged) then it could be your compressor going out. Grab a long screwdriver or an automotive stethoscope to see if you can pin point it. It should not whine.

[Ronvp]

Originally Posted by bruceisla

I think you'll need to define the area of the sound ...I am assuming you are diesel ... normally, the compressor is in the rear (on engine), the dash fan is under passenger dashboard, the vacuum pump is somewhere on the firewall (usually over generator), and the condenser fan is usually lower on chassis (roughly in area of passenger seat underneath). All of these make noise and the locations of components are variable. You can try running the dash defroster without A/C and see what happens. The defroster will utilize the dash fan and vacuum pump.

Sorry for not being clear, I have a diesel pusher, sounds is coming from the front-middle of the coach, right where the compressor is. It is not the dash fan. that does not make much noise at all...

[Selah]

We have, probably, the same whining noise. It comes from the very high speed electric fan on the condenser unit which is directly underneath the drivers compartment. Hardly noticed inside like you said.

[homeless]

It might be a snake skin!!

[Ronvp]

Originally Posted by Selah

We have, probably, the same whining noise. It comes from the very high speed electric fan on the condenser unit which is directly underneath the drivers compartment. Hardly noticed inside like you said.

thanks for that. o will leave it for now and I will ask a mechanic on the next service.

[bruceisla]

Originally Posted by Ronvp

Sorry for not being clear, I have a diesel pusher, sounds is coming from the front-middle of the coach, right where the compressor is. It is not the dash fan. that does not make much noise at all...

I'm not familiar with your RV but most diesel pushers have an engine mounted compressor (like a car) that has very long hoses all the way to the front. At the front is is the conventional stuff but in weird places (condenser, evaporator, a condenser fan, a 12vdc vacuum pump to operate the deflectors, and a dash circulation fan).

In other words, on a diesel pusher, you hear compressor noise by standing at the rear radiator area.

The condenser, which in a car is behind a front radiator, is a standalone unit that is normally in the airstream down low in the driver or passenger area under the coach. It will have a separate fan ... like a front wheel drive transverse car since it can't use the mechanical fan normally on the front of an engine.


Welcome to diesel pushers !! .... you will be doin' a whole bunch of WHAAAT?

As mentioned, the sound is probably the condenser fan. I can definitely hear mine when it engages. Typically, it does not run unless the dash A/C is running ... it's off with defroster/dash heater/non AC fresh air.

[jrgreen]

Ron, you can search this forum and find previous posts about this situation. It seems that is it what it is. As far as I know no one has found a fix. This is real disheartening since my 2008 does it and a 2013 still does it...I would have thought it would have been fixed by now. If you find a fix, please post it here. thanks.

[palehorse89]

[QUOTE=homeless;1903373]It might be a snake skin!![/QUOTE]

OH My God Ron, ..........Welcome!

( http://www.irv2.com/forums/f258/foun...in-191033.html )

[Ronvp]

Thanks for all the help.. I will take a look at the condenser Fan and see if there is anything that can be done to make it less noisy.. if not we just have to live with it..